Stringed instruments, such as guitars, ukuleles, and violins, produce sound through the vibrations of their tightly stretched strings. The sound produced by a stringed instrument consists of two components: sound directly produced by the vibrations of a string (vibration sound) and sound produced by the resonance of the body (housing) of the stringed instrument accompanied with the vibrations of a string (resonant sound). Each of these sound components of a stringed instrument is converted into electrical signals which will be amplified with an amplifier. Pickups are known as mechanisms that convert such sound components of stringed instruments into electrical signals and output them.
The pickups are classified into several types, each of which has its own characteristics. For example, an “in-bridge pickup,” incorporated in bridge of a stringed instrument, converts the vibrations of the strings into electrical signals and outputs them. Thus, the in-bridge pickup can decrease the proportion of other sound components than that generated by the vibrations of the strings compared with collection of sound through a microphone provided close to the strings, so that the in-bridge pickup is suitable to efficiently output the sound of the strings. However, the in-bridge pickup is unsuitable for the output of the eigentone of the body of the stringed instrument (e.g., the resonant sound from the housing).
An “attachable pickup,” which is attached to the body of a stringed instrument, converts sound from a housing into electrical signals and outputs them. Thus, the attachable pickup is more suitable for the output of the eigentone of the stringed instrument body than the in-bridge pickup. The attachable pickup, nevertheless, must be tuned depending on complicated vibration characteristics of the housing since this pickup is attached to the surface of the housing with a dual sided tape or an adhesive. Furthermore, this pickup may cause scratches on the surface of the housing. The attachable pickup thus involves troublesome fixation and tuning.
Another type of pickup intended to address such circumstances has been disclosed, for example, in Japanese Patent Laid-Open No. 2006-47946. This pickup is fixed through a piezoelectric element close to a bridge without an adhesive. The pickup disclosed in the unexamined patent can convert the vibrations of a housing into electrical signals; hence, the pickup can accurately output the intrinsic sound of the stringed instrument, including the resonant sound component of the housing, in addition to the vibrational sound component of the strings. Unfortunately, the pickup disclosed in Japanese Patent Laid-Open No. 2006-47946, which is also fixed to the housing, requires attachment and tuning. Moreover, the risks of scratching the surface of the housing still remain.
The conventional pickup mechanisms have both advantages and disadvantages as described above. Thus, characteristics required for a pickup are simple attachment and tuning, and ready output of both direct vibrational sound of the strings and intrinsic sound of the stringed instrument.